Heat treating apparatus



june 22, 143. MCGUIRE, JR 2,322,395

HEAT TREATING APPARATUS Filed Jun e' 15, 1940 I 6 Sheets-Sheet l 1INVENTOR '52 FRANK MGGLJIREJR.

ATTORNEY June 22, 1943. MCGUIRE, JR

HEAT TREATING APPARATUS Filed June 15, 1940 6 Sheets-PSheet 2 lmwINVENTOR FRANK McGUlRE,JR.

ATTORNEY F. MCGUIRE, JR 2,322,305 1 June 22, 1943.

HEAT TREATING APPARATUS 6 Sheets-Sheet 3 Filed June 15; 1940 INVENTORATTORNEY FRANK Mc GUIRE,JR

June 22, 1943. F. M GUIRE, JR

HEAT TREATING APPARATUS Filed June 15, 1940 6 Sheets-Sheet 4 R E m Rw a0 N M m m FYA w m w June 22, 1943. F, MCGUIRE, JR, 2,322,305

A HEAT TREATING APPARATUS Filed June 15, 1940 j 6 Sheets-Sheet 5INVENTOR FRANK MCGU|RE,JR.

ATTORNEY June 22, 1943.

F. M GUIRE, JR

HEAT TREATING APPARATUS Filed June 15, 1940 6 Sheets-Sheet 6 INVENTORATTORNEY surface.

Patented June 22, 1943 HEAT TREATING APPARATUS Frank McGuire, Jr.,Bogota, N. J., assignor to The Linde Air Products Company, a corporationof Ohio Application June 15, 1940, Serial No. 340,645 12 Claims. (Cl.266-) This invention relates to heat treating apparatus useful forlocally hardening surface portions of metal bodies, such as gear teeth,and more particularly to apparatus which includes a device foraccurately positioning a pair of blowpipe heads in operative relationwith respect to a gear tooth.

A particularly effective manner of locally hardening a surface of ametal body, such as a side or wearing surface of a gear tooth, consistsin applying high temperature heating flames followed by cooling jetsagainst successive portions of the It is particularly desirable toharden both sides or wearing surfaces of a gear tooth simultaneously, toavoid the possibility of reheating a previously hardened surface, and.also to obviate the possibility of causing warpage due to localexpansion and contraction of one side only of the tooth. To secure themaximum benefits from hardening both sides of the tooth simultaneously,it is desirable to position the heating flames, and also the coolingjets, exactly opposite each other on opposite sides of the tooth. It isalso desirable that the flames on each side of the tooth impinge uponthe tooth surface at the same angle; and that the blowpipe heads, fromwhich the heating flames and cooling jets normally are discharged, bespaced the same distance from each tooth surface. On the one hand, it isnecessary that the blowpipe heads be positioned with extreme accuracy,but, on the other hand, too much time should not betaken to position theheads, because the apparatus lies idle during positioning and the costof treatment is thereby increased.

In accordance with previous practices, a drill is inserted in eachblowpipe head, in one of the outlets from which the heating flames aredischargedin order to adjustthe distance between each head from thetooth, to determine the points at which the flames will impinge upon thetooth surface, and to determine the angle of impingement of the heatingflames and cooling jets. Insertion and reinsertion of a drill in aheating flame outlet tends to mar the outlet and there'- by lower theefficiency of the head, since an irregularity in an outlet tends tocause the heating flame discharged from that outlet to burn improperly,thus tending to produce backfires and flashbacks. Moreover, such amethod of, positioning the heads requires considerable time, and only ahighly skilled operator can position the heads with the highest degreeof accuracy. Also, the correct set-up for a particular type and size oftooth cannot be duplicated at some later time without repeating theentire setting-up operation.

Among the objects of this invention are to provide apparatus for heattreating gear teeth which include a novel positioning device by which apair of blowpipe heads may easily be adjusted to any predeterminedposition relatively to a gear tooth; to provide such a positioningdevice by which the heads may be assembled accurately in v I position ata work bench or any other convenient place, and the heads then attachedto the remainder of the apparatus with assurance that the heads willbe'in accurate position relatively to the gear tooth to be treated; toprovide such a positioning device which will hold the heads accuratelyin position during treatment of a gear tooth; to provide heat treatingapparatus in which the pressure of quenching liquid is maintainedconstant; to provide such apparatus by which a pair of blowpip heads maybe supplied with a combustible mixture of gases from a single blowpipeand also may be supplied with a quenching medium from a single sourcethereof; and to provide apparatus for heat treating gear teeth by whicha pair of blowpipe heads may be supported for universal movement in aplane. Other objects and novel features of this invention will becomeapparent from the following description and accompanying drawings, inwhich:

Fig. 1 is an end elevation of apparatu constructed in accordance withthis'invention, in which a pair of blowpipe heads are held by a v novelpositioning device in inoperative relation with respect to a tooth of agear;

Fig. 2 is a perspective view, looking downwardly at a small angle,illustrating more particularly the positioning device and attachedblowpipe heads of Fig. 1;

Fig. 3 is a rear elevation of the positioning device and blowpipe headsof Fig. 1;

Fig. 4 is a rear elevation of an altemative structed in accordance withthis invention for supporting a pair of blowpipe heads for universalmovement in a plane, and by which the blowpipe heads may be suppliedwith a. combustible mixture of gases from a single blowpipe and acooling medium from a single source;

Fig. 9 is a horizontal sectional. view, looking downwardly along line -8of Fig. 8;

'Fig. 10 is a vertical sectional view taken along line l0ll of Fig. 8,and showing more particularly a manifold which forms a portion of theapparatus illustrated in Fig. 8;

Figs. v11, 12, and 13 are vertical sectional views taken along linesl|l|, |2-l2, and l3-l3, respectively, of Fig. 10;

Fig. 14 is a longitudinal sectional view illustrating a header whichforms a portion of the apparatus of Fig. 8; I

Fig. 15 is a front elevation of the header of Fig. 14, partly brokenaway to show the interior construction;

Fig. 16 is a vertical sectional view taken along line I6-l6 of Fig. 15;A

Figs. 17 and 18 are longitudinal sectional views of the right handblowpipe head of Fig. 3, taken along lines l'|-'-i1 and iii-I8,respectively;

Fig. 19 is an end elevation, partly broken away. on an enlarged scale,of the blowpipe heads of Fig. 1 and a modified form of positioningdevice through which a cooling medium may be circulated;

Fig. 20 is a transverse sectional view taken along line 20-20 of Fig.19;

Fig. 21 is a side view of the right hand blow pipe head of Fig. 6; and

Figs. 22 and 23 are longitudinal sectional views slide 1 by a bolt II,

and arm 10 is slotted, so that a slotted vertical arm I2 is movablealong arm l0, and may be secured thereto in any desired position by abolt I! which extends through the slot in arm l0. A slide I4, to whichblowpipe B is secured by a clamp I5, is similarly adjustable alonghorizontal arm 10. A slide ii, to which blowpipe B i secured by a clampI1, is. movable vertically along arm i2. Slides I4 and I6 respectivelymay be secured in any desired vertical or horizontal position by boltssimilar to bolt l3 and which extend through the slots in arms i0 and I2,respectively. Thesupport S.

Ithrough slides i4 and liand clamp l5 and ll,

taken along lines 2222 and 23-23, respectively,

of Fig. 21.

The apparatus illustrated in Figs. 1-3 comprises, in general, a pair ofblowpipesB and B mounted on a support S, in turn mounted on a carriageC; a pair of heating heads H and H clamped in a positioning device D andsupplied with a combustible mixture of gases by blowpipes B and B; and aquenching medium supply Q, which supplies heads'H and H with a quenchingmedium at substantially constant pressure. The heads H and H, as in Fig.1, are in operative position for hardening oppositely disposed wearingsurfaces of a tooth T of a gear G. Gear G of Figs. 1 and 2 hasrelatively small teeth, and there is thus insuilicient room between twoteeth for a head to enter completely. Heads H and H are therefore soconstructed'that the heating flames and cooling jets are dischargedagainst permit vertical and radial adjustment of blowpipe piDe'B'.

The support S herein illustrated is similar to that disclosed in theapplication of Roger 0. Day, Serial No. 169,373, filed October 16, 1937,now U. S. Patent No. 2,224,006 but other supports may be used, such asthat disclosed in the application of Roger B. White, Serial No. 169,379,filed October 16, 1937, now U. S. Patent No. 2,224,007.

Blowpipes B and B are each supplied with a combustion supporting gas,such as oxygen, and a combustible gas, such as acetylene. bustiblemixture of these gases is formed within the blowpipes, the proportionsof the combustible mixtures being adjusted by regulating valves l8. Fromthe forward end of each blowpipe, as in Fig. 2, the combustible mixturepasses through a tube iii to the upper end of a header 20. From thelower end of each header, the combustible mixture passes through a tube2! to head H or H. Tubes 19 and 2| are provided with unions 22 and 23,respectively, so that heads H and H may be adjusted to any desiredposition. Heads H and H are preferably secured in positioning device Dat a workbench or any other convenient place, headers 20 being moved tothe necessary positions when the heads H and H The quenching mediumsupply means Q includes a manifold 24 having at one end an inlet thetooth surfaces from the lower end of each head, rather than from theside of each head, which is possible when larger gear teeth are beingtreated and the heads can be positioned between the teeth, as in Fig. 6.For moving the heads along the tooth, or downwardly in Fig. 2, carriageC runs along a flanged track T, which is preferably positioned with theflanges parallel to the center line of the tooth being treated, so

that the heads H and H will traverse a path which is parallel to thesides of the tooth. Carriage C is constructed as disclosed in U. S.Patent No. 2,183,605, being a four wheeled self-propelled mechanism. butit will be understood that any other suitable traversing mechanism orcarriage may be utilized.

Carriage C is provided with a slide4 adjustable laterally by a handwheel 5, while a vertical uide 6 is secured to the end of slide 4. Aslide 1, which fits into vertical grooves in guide 6, is moved upwardlyor downwardly by a screw 8 which may be turned by a hand wheel 9. A

25 through which a cooling medium, such as water, is supplied. Leadingfrom the. side of the manifold are a pair of tubes 26, which conduct thecooling medium to heads H and H. Tubes 26 are preferably relativelyflexible, so that each tube may easily be connected to head H or Hirrespective of the position in which the heads are placed. Leading fromthe end of the manifold. opposite inlet 25, is a vertical pipe 21provided witha Valve 28; The upper end of vertical pipe 21 is providedwith a packing gland 29 which surrounds an overflow pipe 30, which maybe moved upwardly and downwardly to any desired vertical position. Thepressure of water through inlet 25 is preferably adjusted so that asmall amount of water flows continuously from the open upper end of pipe30. When the horizontal arm I0 01' support S is attached to pressure ofthe cooling medium in manifold 24 exceeds a predetermined value, excesscooling medium will flow out of the open upper. end of overflow pipe 30.Thus, the pressure of cooling medium supplied to heads H and H willremain essentially constant, and the pressure of cooling medium suppliedto each head will be the same. In addition, if the flow or water throughthe open upper end of pipe 30 ceases, this will indicate a lack ofsumcient pressure, and serves as a warning to the operator that theheadsmay A com-' become overheated, or the-heated surface portions may beinsufficiently quenched. If it is not desired tensebverflow pipe 30 toregulate the pressure of cooling medium, valve 28 may be closed.

The positioning device D, as in Figs. 1-3, includes a pair of arms 3|and 32 which are pivotal about a common center. are symmetrical, i. e.,they are similar in shape but reversed in configuration, and the upperend of each arm is formed as a relatively narrow cylindrical segment 33or 34. Cylindrical segments 33 and 34 are interfitting and have equalradii, the arms being pivotal about a stud 35 which extends rearwardlyfrom the center of cylindrical segment 34 and passes through an aperturein a leveling plate 36 and thence through an aperture in the center ofcylindrical segment 33. Arms 3| and 32, which are thus pivotal about thecenters of cylindrical'segments 33 and 34 as a common center, may besecured in any desired radial position with respect to each other and/orplate 36 by tightening a wing nut 31 on stud 35. The lower ends of arms3| and 32 are provided with wide, deep slots 38 and 39 in which heads Hand H may be secured by clamping plates 40 pressed against the heads bywing bolts 4|.

In order that any given set-up may be duplicated readily, thepositioning device D, and preferably also heads H and H, are providedwith means for indicating the radial positions of arms 3| and 32 and thelongitudinal position of heads H and H relative to the arms. Inaddition, at the upper end of plate 36 i a, leveling surface 42, with aU notch 43 formed centrally thereof and extending down to the peripheryof cylindrical segments 33 and 34. In the bottom of notch 43 is anindicating mark 44 which cooperates With scales 45 and 46 in settingarms 3| and 32 in any predetermined radial position about their commoncenter. Scales 45 and 46 are preferably graduated in degrees and may bestamped or etched around the periphery of cylindrical segments'33 and34, respectively, or stamped on metal strips which are aflixed to theperiphery of the cylindrical segments by rivets. Scale 45 is stamped on,or aflixed to, the periphery of cylindrical segment 33, and scale 46 isstamped on, or aifixed to cylindrical segment 34, but reads in theopposite direction from scale 45. Consequently, arms 3| and 32 may beplaced in identical positions about their common center, 'or atidentical angles with respect to leveling surface 42,'or a.perpendicular thereto, merely by aligning identical marks on scales 4'5and 46 with indicating mark 44. For instance, as illustrated in Fig. 2,each arm is set at an angle of 50 with respect to leveling surface 42,or at an angle of 40 with respect to a perpendicular to the levelingsurface.

Each arm 3| or 32 is also provided with an indicating mark 41 adjoiningslot 38 or 39, each mark being spaced the same:- distance from the edgeof thearm. To cooperate with mark 41, a suitable scale 48, preferablyreading in. inches or increments thereof, is stamped or etched on eachhead, as in Fig. 3. identical marks on each scale 48 with indicatingmarks 41, heads H and H" may be placed in exactly correspondingpositions in slots 38 and 39.

Any particular setting of the blowpipe heads H and H, or other headsadapted to be used in connection with the positioning device, may beeasily and quickly repeated once the correct position has beendetermined for any particular gear tooth. Assuming that the angularsetting Arms 3| and 32 I gt arms 3| and 32 and the proper position ofeads H and H in slots 38 and 39 are known, the positioning deviceand theheads aretaken to a workbench-or other suitable place, where they may beassembled easily and quickly. After the proper marks on scales 45 and46, indicating the same number of degrees, are aligned with indicatingmark 44, arms 3| and 32 are clamped in the proper radial position bytightening wing nut 31. Then heads H and H are secured in slots 38 and33 by tightening wing bolt's4l, the same distance mark on each scale 48being aligned with indicating mark 41. The assembled positioning deviceand heads are then taken to the work set-up and the heads H and Hconnected to unions 23, blowm'pes Band B having been placed in parallelrelationship by proper adjustment of vertical arm l2 and slides I4 andI6. Before unions 22 and 23 or clamps l5 and H are tightened, a level isplaced on surface 42 and heads 20 or blowpfpes B and B twisted so thatsurface 42 is exactly level. This will' place the centerof stud 35 andindicating mark 44 in vertical alignment. In addition,

- blowpipe B or B may be moved forwardly or backwardly in clamp |5 orl1, as necessary, so

that each head will be the same distance from arm I0, which ispositioned at right angles to the centerv line of a shaft 49, upon whichgear G is, mounted, and consequently also at right I angles to thecenter line of tooth T. Clamps l5 and I1 and unions 22 and 23 may thenbe tightened, and tubes 26 attached to the heads.

The gear G is supported so that the center line of tooth T is vertical,and the entire assembly of support, blowpipes, heads and positioningdevice are then moved laterally, if necessary, by moving laterallyadjustable slide 4, so that the centers of stud 35 and indicating mark44 are in exact vertical alignment with the center line of tooth T.(This is relatively easily done, for the center line of shaft. 49 isalso in vertical alignment with the center line of tooth T.) Then theentire assembly, if necessary, is raised or lowered by adjusting thevertical position of tooth merely by adjusting the positioning deviceMerely by aligning V coincide with indicating marks 44 and 41.

and the heads clamped therein to positions in which the proper marks onscales 45, 46, and 48 In repositioning'the heads,"it is normallyunnecessary to'change the position of slides I4 and It or loosen clampsl1, since a slight rotation of headers 20 will take care of anydifierence in the distance between the heads for a different tooth. Theonly other adjustment which probably will be necessary will be avertical adjustment of the entire assembly to place surface 42 theproper distance above the top of tooth T. In connection with the use ofthe. positioning device of this invention, it is desirable to providetables indicating the proper angular setting of arms 3| and 32 and theproper setting of heads H and H'in slots 38 and 39, as well as theproper distance of surface 42 above the top of the tooth,

for each size and typ of tooth to be treated.

The positioning device D of Figs. 1 to 3 may remain attached tothe headsH and H, since the teeth being treated are relatively small and. theheatv to which the positioning device is exposed will normally not besumcient to damage the same. However,'if desired, acooling medium maybe. circulated through the positioning device, particularly through thelower ends of arms II and 22. As shown in Figs. 19 and 20, arms II and.22f arehollow but otherwise's'imilar to arms 8| and 32 of Figs. 1 to 3,so that a suitable cooling medium may be circulated, therethrough frominlets I to outlets IOI.

' The positioning device D of'Figs. 4-7 is similar to the positioningdevice D just described,

' but, includes means for adjusting the relative 7 height of thepositioning device and heads with respect to the top of a gear tooth androtatable clamps at the lower end of the pivoted arms by whicli'bthertypes of heads may be accurately positioned. Thus, the positioningdevice D includes a pair of symmetrical arms -5I and 52 turiinal heatingpassage I05 and cooling fluid passage I06 parallel thereto. Thecombustible mixture is supplied through inlet connection 2|, while thecooling fluid is supplied through an inlet connection [06, to which tube26 of Figs. 1-3 is connected; w

Heads H" andH"'- are similar to those disclosed in the aforementionedRoger 0. Day ap- 'plication Serial No. 169,373, now U. S. Patent No.

2,224,006. Head H2" is illustrated in greater detail in Figs. 21-23,head H" being similar but asymmetric to head H". Head H" is providedwith a surface II5 which is inclined to the sides of the head and formsone surface of, a lower portion I I6, which forms a lower end of reducedthickness and permits the head to be inserted between two closely spacedgear teeth. I The head H" is also provided with an inlet III to whichthe combustible mixture conduit 2I' may be which'are pivotal about acommon centerand the upper ends of which are formed as cylindricalsegments 63 and '64 having equal radii. Asbefore, the cylindricalsegments interfit'and are provided with scales 45' and 46' which read inopposite directions and which may be stamped or etched on theperipheries of the cy- I lindical segments, '01 stamped on metal stripsriveted to the arms. Scales 45 and 46' cooperate with an indicatirm mark44' on the side of a plate 53 provided with an upper leveling surface42'. Arms 5I and 52 are pivotalabout a stud 54 extending outwardly fromplate 53 and passing centrally through cylindrical segments'fland 64',plate 53 being disposed outside the cylindrical segments, ratherthanbetween them, in order to accommodate the means for positioning thedevice the proper distance above the top of the tooth and in verticalalignment with the center line of the tooth, which will be describedlater. As before, arms 5| and 52 may be clamped in any desired radialposition by a wing nut 31'. 5

. The lower ends of arms 5| and 52 are formed as cylindrical segments 55and 56, respectively. Cylindrical clamping blocks 51 and 58, each havingradii equal to those of cylindrical segconnected, and passages Ill andII! which lead the combustible mixture to a distributing cham- Jber I20in the lower end of the head. A plurality of heatinggas outlets I2I ofsubstantially equal diameter lead from the chamber. I20, terminating inthe surface H5, and are preferably disposed in staggered relationinsubstantially vertically rows, so that the heating Jets produced willtend to overlap and produce a more even heating effect. -In addition,the distance between centers of adjoining outlets I2I increasesprogressively from the lower to the upper end of each row. Outlets I2Iare spaced pro- .gressiv'ely further apart upwardly from the lower endof each row, so that closely adjoining heating jets will apply agreateramount of heat adjacent the root of the tooth and a progresssivelylesser amount upwardly towards the top of the tooth.

The passage II9 may be disposed substantially perpendicularly to thechamber I20, sothat the combustible mixture will not be projecteddirectly into the upper of the outlets I, and a uniform distribution ofthe combustible mixture to all of the outlets I2I will be obtained. Thepassage II8 may be drilled from the upper end of the head and thepassage II9 from the surments-65 and 56, are rotatably secured to thereading in degrees and stamped around th periphery of the block, whichcooperates with.a suitable indicating mark 62 on cylindrical segment 55or (see Fig. 5). Scales 6I read in opposite directions, while scales 6Iand indieating marks 62 are placed in exactly corresponding positions onblocks 51 and 56 and cylindrical segments 55 and 56, respectively.

Each clamping block is provided with a wide, deep slot 63, in whichheating heads H and H of Fig. 4, or heads H" and H' of Figs. 5 and 6,may be secured by clamping plates 40' pressed against the heads by setscrews 64. When a different type of head, such as heads H" and H' ofFigs, 5 and 6, is used in hardening a large gear tooth T, each clampingblock is rotated through 180 and attached to the upper end of: thehead.- As in Figs; 17 and 18, head face II5, the ends of the passagesbeing closed.

by suitable means, such as plugs I22 which are secured in the ends ofthe passages in a suitable manner, such as by welding or brazing. Thedistributing chamber I20 may be formed by a suitableslot in the lowerportion of the head,

. the outer periphery of the slot being closed by a substantiallyU-shaped strip I23 securedto the head in a suitable manner, such as bywelding or brazing.

The head H" is also provided with an inlet I25, to which the cooling andquenching fluid conduit 26 may be connected and from which an inclinedpassage I26 leads downwardly through the head to a distributing chamberI21, disposed alongside of and substantially parallel to the combustiblemixture distributing chamber I 20. A plurality of quenching fluidoutlets I26 lead from the distributing chamber I21, terminating in theinclined surface I I5 of the head, and are preferably inclinedrearwardly and away from the heating gas outlets, desirably at an angleof about 30, so that the quenching Jets will not interfere with theheating flames. The quenching outlets I28 are also disposed in aplurality of rows so as to obtain complete quenching without splashingand interference with the heating flames. Inasmuch as the quenchingoutlets are inclined at an angle to the direction directing passagesimilar to the heating gaspassage I I9. The passage I28 and chamber I21may be drilled from the top of'the head and lower portion H8, and theopen ends thereof closed by suitable means, such as plugs I29 which aresecured therein in a suitable manner, such as by welding or brazing. 1

Indicating marks 85, as in Fig. 4, are placed in corresponding positionson clamping blocks 51 and 58 alongside slots 83, to cooperate withscales 48 on heads H and H, respectively, so that the heads may bepositioned properly in slots 83. Heads H" and 11" may be provided withscales similarly stamped or etched thereon, or provided with indicatingmarks, as shown.

Heads H and H' are of a type normally used in treating only one size ofgear tooth,.i. e. 1 D.P. (diametral pitch), 1 /2 D.P., 2 D.P., 3 D.P.,or '4 D.P., while heads H and H' are of a type adapted to treat either 5or 6 D.P. Thus, heads H" and H will normally require only a singlesetting, and a single indicating mark will suflice for such setting.Also, in many instances, a single indicating mark will sumce on heads Hand H, when positioned by device D.

A groove 51 is formed in the front of plate 53, as in Fig. 7, in which abar 88 is slidable perpendicularly to surface 42'. The upper end of bar88 is slotted, and a stud 69, extending forwardly from plate 53 orformed as an extension of stud 54, extends forwardly through the slot inbar 58. Bar 88 may be clamped in any desired position by tightening awing nut III on stud 89. The lower end of bar 88 is provided with a forkII, and an indicating mark I2 on bar 88 cooperates with a scale I3,etched or stamped on plate 53 along one side of groove 61, to permit bar88 to be placed in the correct position in groove 81, as in Fig. 7.Heads H and H, or heads H" and H', are clamped in the correctlongitudinal position in clamping blocks 51 and 58, and arms 5| and 52are clamped in the correct radial position, at a workbench or othersuitable place, as previously described for positioning device D. Inaddition, bar 68 is clamped in the correct position by aligningindicating mark I2 with the correct mark on scale I3.

After the positioning device D and heads have been assembled, the headsare connected to headers 20, surface 42' leveled, tubes 28 connected tothe heads, and unions 22 and 23 and clamps I5 and I! tightened, aspreviously described. With surface 42' level, the axis-of the two headswill be in a vertical position parallel to the axis of tooth T or T'.the correct position, the common center of arms 5| and" 52 is placeddirectly above the center line of tooth T and the heads placed incorrect posithe heads will be correctly positioned with respect to thetooth, all automatically. When relatively small teeth are being treated,the positioning device D may remain afllxed to the heads, except bar 68is moved upwardly to the position of Fig. 4, to prevent damage to thesame. when larger teeth are being treated, as in Fig. 6, the positioningdevice D' is preferably removed. If desired, and previously pointed out,a cooling medium may'ebe circulated through the positioning device D,particularly through clamping blocks 51 and 58 and the lower ends ofarms5| and 52, and the device left clamped to the heads during hardening.

Further in accordance with this invention, apparatus may be constructedby'which the blowpipe heads are movable universally in a plane, andsupplied with a combustible mixture of gases from a single blowpipe andwith a cooling medium from a single source. As illustrated in Figs. 8 to16, such apparatus may include a manifold I5, having a combustiblemixture inlet I8 at the rear end thereof, to which a nipple II at,-

tached to'the forward end of a blowpip B is secured. Thecombustiblemixture is led from inlet I6 into a passage I8 extendingtransversely of the manifold, and thence to outlets I9 at either end ofpassage I8 and drilled from the front of the manifold. The manifold isalso provided with a transverse cooling fluid passage 88, to one end ofwhich a valve BI is connected and to the opposite end .of which apressure gauge 82 is connected. A suitable cooling fluid, such as water,is supplied by a hose 83 to valve 8|, which controls the flow of coolingfluid to passage 88, gauge 82 being utilized in adjusting the pressureof the cooling fluid. Disposed centrally of passage 88, and drilled inthe front of the manifold, are a pair of cooling fluid outlets 84.

The apparatus also includes a pair of headers 85, which aresubstantially identical in construction. As in Figs. 14 to 16, eachheader is provided with a combustible mixture inlet 86 at the upper endthereof leading to a central passage Unless already in tion with respectto the sides of the tooth, by

sembly, including the blowpipe support, is moved upwardly or downwardly,and laterally to either side, as the case may be, until fork II engagesthe top edges of the tooth, as in Fig. 6. Since I surface 42' is levelor horizontal, andbar 88 is perpendicular thereto or vertical, when thearms of fork, II engag the top edges of the tooth, the common center ofarms 5I and- 52 will be disposed directly above the center line of thetooth and 81, and a cooling fluid inlet 88, in alignment with anddisposed on the. opposite side of the header from the combustiblemixture inlet and leading to a cross passa e 89. From each end of crosspassage 89, a pair of longitudinal passages 98, parallel to centralpassage 81, carry the cooling fluid' down through the header. From thelower end of each longitudinal passage 98, a pair of transverse passages9| lead the cooling fluid to each end of a cross passage 92, while acoolingfluid outlet 93 connects centrally with cross passage 92. Also atthe lower end of each header, and disposed opposite to but in alignmentwith cooling fluid outlet 93, he; combustible mixture outlet 94,disposed between cooling fluid passages 9I and connecting with the lowerend of central passage 81. In addition, combustible mixture outlet 94 ison the opposite side of the header from combustible mixture inlet 88,and, similarly, cooling fluid outlet 93 is on the opposite side of theheader from cooling fluid inlet 88.

A pair of nipples and a union 95 connect the combustible mixture inlet86 at the upper end of each header with one of the combustible mixtureoutlets- I9 in the manifold, while a tube 98, bent around as in Figs. 8and 9, connects cooling fluid inlet 88 in each header with one of thecoolingfluid outlets 84 in the manifold. Secured in the combustiblemixture outlet 94 at the lower end of each header is a suitable nippleconnecting with a union 23' to'lead the com-,-

convey the cooling fluid to each head from cooling fluid outlets 93 atthe lower end of each header 85. The nipples attaching unions 23" and 95to the manifold 15 and/or headers 85 maybe secured in the respectivecombustible 3. A device for positioning a pair of blowpipemixture inletsand outlets of the manifold or headers in any suitable manner, such asby weld-- ing or silver soldering, while nipples connecting suitableunions provided at the ends of tubes 26' and 86 may similarly be securedin the respective cooling fluid inlets and outlets of the manifold andheaders. Tubes 2| and 26' are connected to the respective combustiblemixture and cooling fluid inlets of heads H and H, or'

heads H" and H",', in the same manner as the connecting tubes previouslyreferred to.

.Since the respective inlets and outlets in the headers are disposeddirectly opposite each other, each header 85 may be moved throughsubstantially a complete circle, 1. e. about the inlets at the upperends thereof. Consequently, the upper ends of the heating heads may beplaced in any position about this circle. Furthermore, the tubes 26 alsomay be rotated through almost a complete circle, so that the headsthemselves may be rotated about the combustible mixture tubes 2| as anaxis. Thus, the heating heads are adjustable to any position in a plane,and therefore are substantially universally adjustable. As will beevident, positioning device D or B may be utilized in conjunction withthe manifold, headers, etc. of Figs. 8-16.

It will be apparent from the foregoing description that apparatusconstructed in accordance with this invention not only includes aposition'ing device by which any particular predetermined position of apair of blowpipe heads may be obtained with speed and-accuracy, but alsoprovides means whereby a uniform and constant flow and pressure of thecooling fluid oi the heads can be obtained, as well as means whereby theheads may be made universally adiustable in a plane.v It will-beunderstood that other blowpipe heads than those described may be used,that types of connections diifering from those described may be used,and that various changes in the apparatus may be made without departingfrom the spirit and scope of this invention, as defined in the appendedclaims.

What is claimed is:

1. A device for positioning a pair of separately supported blowpipeheads for hardening gear teeth or the like, comprising a pair of armspivotal about a common center; means for indicating the angular positionof each arm about said common center comprising a scale on each armindicating the number of degrees of rotation of each arm withrespect tosaid common center, one scale reading from a lower to a higher number ofdegrees in the opposite direction from which the other scale reads; andmeans for removably securing one of said heads to each arm. 2. A devicefor positionihg a pair of blowpipe heads for hardening gear teeth or thelike, comprising a pair of arms pivotal about a common center; means forremovably securing one of said heads to each arm; and a fork forengaging the top of a gear tooth, said fork being movable toward andaway from said gear tooth andbeing adapted to be secured in a relativelyfixed position so as to space said device the proper distance from thetop of said gear tooth,

heads as deflned in claim 2, said device including means for indicatingthe relative position of said fork with respect to said device.

4. A removable device for positioning apair of blowpipe heads,comprising a pair of arms pivotal about acommon center; a plate providedwith a level indicating surface; means for indicating the angularposition of each arm about said common center; and means for removablysecuring one of said" heads to each arm, said device being soconstructed and arranged that said common center may be disposed abovethe center of a gear tooth having its t0p surface disposed substantiallyhorizontally, and said level indicating surface may be positionedsubstantially horizontally and substantially parallel to the top surfaceof said gear tooth, whereby each 1 head 'will be positioned accuratelyin operative relation with respect to one of the opposite sides of saidgear tooth.

5. A device for positioning a pair of blowpipe heads for hardening agear tooth having its top surface disposed substantially horizontally,as defined in claim 4, in which the upper end of each arm is shaped toform a cylindrical segment, and also in which said indicating meanscomprises a mark on said leveling plate and a scale on each cylindricalsegment indicating the number of degrees of rotation ofeach arm withrespect to said indicating mark, one scale reading from a lower to ahigher number of degrees in an opposite direction from which the otherscale reads.

6. Apparatus for heat treating gear teeth or the like comprising a pairof blowpipe heads; means for supporting said blowpipe heads; and aseparate device for positioning said heads, each in operativerelationship-with respect to one of the opposite wearing surfaces of agear tooth.

. said device, comprising a pair of arms pivotal about a common center,means adjacent one end of each arm for indicating the angular positionof said arm about said common center, and means for removably securingone of said heads to each arm, said means comprising a radiallyadjustable clamp pivotally secured to the other end of each arm.

7. Apparatus for heat treating gear teeth or the like as defined inclaim 6, in which said device includes means for indicating the radialposition of each clamp relative to the respective arm to which it issecured.

8. Apparatus for heat treating gear teeth or the like as defined inclaim 6, in which said heads are adapted to be secured by said clamps invarious positions'longitudinally of said heads, and. in which saiddevice includes means for indicating the longitudinal position of eachhead with respect to the clamp by which it is secured.

9. Apparatus for heat treating a gear tooth or the like having an uppersurface normally disposed substantially horizontally, comprising a pairof'blowpipe heads; means for supporting said blowpipe heads; and aseparate device for a fork movable upwardly and downwardly for'positioning said device in vertical alignment with the center line ofgear tooth, and means for removably securing one of said blowpipe headsto each arm.

10. Apparatus for hardening the oppositely disposed wearing surfaces ofa gear tooth or the like comprisinga pair of blowpipe heads, eachadapted to direct at least one high temperature heating flame and acooling medium against successive portions of one of the oppositesurfaces 0! said gear tooth; means for supplying a combustible mixtureof gases; means for supplying a cooling medium; a manifold havingcombustible mixture and cooling medium inlets connected with therespective supply means, and passages leading to two combustible mixtureoutlets andtwo cooling medium outlets; a pair of headers, each having atits upper end combustible mixture and cooling medium inlets and at itslower end combustible mixture and cooling medium outlets, said headersalso having passages leading from the combustible mixture and coolingmedium inlets to the respective outlets, said inlets and outlets beingdisposed-substantially in alignment on opposite sides of said headers atthe upper and lower ends thereof; means connecting one of thecombustible mixture outlets in said manifold with the combustiblemixture inlet at the upper end of each header; means connecting one ofthe from the outlets in the other header to the other blowpipe head.

11. Apparatus as defined in claim 10, including two headers, in each ofwhich the combustible mixture inlet is disposed on the opposite side ofthe header from the combustible mixture outlet and the cooling mediumoutlet is disposed on the opposite side of said header from the coolingmedium inlet.

12. Apparatus for hardening oppositely disposed surfaces of gear teethor the like, comprising, in combination, apparatus as defined in claim10; and adevice for positioning said blowpipe heads, said positioningdevice comprising a pair of arms pivotal about a common center, meansfor indicating the angplar position of each arm about said commoncenter, and means for removably securing one of said heads to each arm.

FRANK MCGUIRE, JR.

CERTIFICATE OF CORRECTION. Patent No. 2,522,505. June 22, 191%.

FRANK HcGUIRE, JR.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction aa followsz Page 1,sec- 0nd column, line 55 for inoperative read -operativ'e-; page 7,first column, line 2, claim 9, before the word 'g eax insert --said-;and'that the said Letters 1 atent should be 'read with this correctiontherein that 4 the same may conform to the record'of the case in thePatent Office.

Signed and sealed this 27mm of July, A. D. 191;

. Henry Van Arada1e, V (Seal) Acting Commissioner of Petenta.

